8/10 overall, just because of everything until around the end of the Osaka arc.
Lamarq said:
Easy.
1. The Aliens want to steer the ship into the planet for revenge, to wipe out both races since their is no alternative planet for their race anyway. But the Alien woman Kei met helps him, they stop the aliens course for the planet in their controlroom. The alien woman initiates self destruct. The humans in suits flee with the ships, but a continious flow of Aliens try to re direct their ship onto earth, so someone has to stay behind and stop from doing that until it explodes.
And that person is Kei. He's sorry he can't keep his promise to his girlfriend on the camera, all of humanity see's how Kei gives his life to protect humanity, no, to protect the ones he loves.
The sky explodes in a huge and silent firework.
And then he becomes a legend of a hero with statues and shit.
And the girl was pregnant ofcourse.
2.OR The aliens had a beam that could shatter the whole Earth, and Kei stopped them from using that beam by destroying it and their hero. But then the aliens suicided their ship into the planet, and there was nothing Kei could do. He failed.A fraction of humanity survived.
He died and is later revived by still functioning underground gantz on the scourged empty surface of what once was Earth.
Millions of different aliens now swarm towards earth, since its easy to populate now, Kei and few others will be the immortal fighters that kill those bastards and try to find still functioning gantz balls etc.It turns out those who have been revived by gantz cant age.
He becomes the merciless monster killing the alien societies on future earth, instead of one of those that protects earth like before.
And maybe Gantz will have a new function.
Revive a loved one:1 million points.
Sounds pretty good. I'd take number 2.